New Hampshire’s top federal prosecutor said Thursday that additional people could be charged as the investigation continues into how a 33-year-old medical technician was able to steal drugs that led to the spread of hepatitis C to at least 39 patients nationwide, mostly at Exeter Hospital.

John Kacavas, the US attorney for New Hampshire, declined to specify who else might be implicated beyond David M. Kwiatkowski, the medical technician who was indicted by a grand jury Wednesday. But investigators combing through records have identified colleagues who worked with Kwiatkowski on cases, as well as staffers at personnel agencies and hospitals who played a role in his employment.

“We will go where the facts take us,” Kacavas said in a phone interview. “I exclude no person or institution.”

Exeter Hospital spokeswoman Debra Vasapolli said Thursday that the hospital has suspended one employee — in addition to firing Kwiatkowski — as a result of its own investigation. She declined to name the individual or why that person was suspended.

Kwiatkowski was arrested this summer based on a criminal complaint, and prosecutors announced Thursday this week’s grand jury indictment of Kwiatkowski for stealing syringes of Fentanyl, a powerful painkiller, while working in Exeter’s cardiac catheterization unit. The indictment referred to his theft of drugs that were intended for seven patients from January to March of this year. They are a fraction of the 32 Exeter Hospital patients who are so far identified as carrying Kwiatkowski’s strain of the liver-damaging virus.

Kwiatkowski, hired as a radiologic technologist, is alleged to have used an elaborate, and particularly dangerous method of stealing drugs. Prosecutors said he grabbed a syringe loaded with Fentanyl, then, to avoid detection, replaced it with a syringe that he had used and re-filled with saline solution — and was tainted with his hepatitis C. Patients who got injections from these used syringes were not only exposed to Kwiatkowski’ s virus, but deprived of the pain-killing medication they were supposed to get, investigators said.

Kwiatkowski’s lawyer, Bjorn Lange, said he had not had time to review the indictment, which replaced charges filed previously. Kwiatkowski, who plead not guilty to the earlier charges, is being held at the Strafford County House of Corrections in Dover, N.H.

Over the years, Kwiatkowski worked in 19 hospitals in eight states, largely getting hired through temporary staffing agencies. He often diffused concerns about erratic behavior by talking about his struggles with Crohn’s disease, an intestinal disorder.

On at least two occasions, while in Pennsylvania and Arizona, he was caught by colleagues with pilfered drugs — though in each case, he wasn’t prosecuted or dogged with negative references.

Kacavas said his office may bring additional charges in the months to come related to other infected Exeter patients, though he said he is conscious of putting forth only the strongest cases and ones in which the victims are strong enough to testify if needed. He said that for each victim, jurors will need to sift through complex evidence related to, among other things, genetic blood testing and viral screening.

Decisions about pursuing prosecutions involving victims from other states will be made by prosecutors in those jurisdictions, he said. So far, six patients in Kansas and one in Maryland have tested positive for the same strain of hepatitis C Kwiatkowski carries.

For each of the seven New Hampshire patients, who were unnamed in this week’s indictment, Kwiatkowski faces two counts — tampering with a consumer product with reckless disregard for the consequences, and obtaining a controlled subject by fraud. In all, he faces 14 charges.

Michael Rainboth, a New Hampshire attorney who represents a handful of clients whose hepatitis C cases have either been conclusively linked to Kwiaktowksi or are suspected of being linked to him, said he is also pursuing the theory that the technician did not act alone. He said he is demanding detailed medical records to track the stolen medications, seeing who may have possibly assisted Kwiatkowski.